AwsAlexaEvent parsing problem

Check this for the parsing of the AwsAlexaEvent


It is expecting and **header** and a **payload** object.

The problem is, when we are testing the lambdas on aws, this is the json provided by the lambda testing tool:

```
{
"version": "1.0",
"session": {
"new": true,
"sessionId": "amzn1.echo-api.session.123456789012",
"application": {
"applicationId": "amzn1.ask.skill.987654321"
},
"user": {
"userId": "amzn1.ask.account.testUser"
},
"attributes": {}
},
"context": {
"AudioPlayer": {
"playerActivity": "IDLE"
},
"System": {
"application": {
"applicationId": "amzn1.ask.skill.987654321"
},
"user": {
"userId": "amzn1.ask.account.testUser"
},
"device": {
"supportedInterfaces": {
"AudioPlayer": {}
}
}
}
},
"request": {
"type": "LaunchRequest",
"requestId": "amzn1.echo-api.request.1234",
"timestamp": "2016-10-27T18:21:44Z",
"locale": "en-US"
}
}
```

As you can see there is no `header` or `payload` objects on this JSON, with ends by returning an empty AwsAlexaEvent.